In a typical autofocus camera, a sensor in the camera detects light (or sound) reflected from the scene in order to determine the distance to the scene. The reflected light can be ambient light and/or light (e.g. infrared light) which is emitted from the camera itself. Once the distance to the scene is determined, the lens system in the camera is adjusted to focus the camera at the scene distance. In order to determine which portion of the scene the autofocus system is sensing, a camera user must look through the camera viewfinder and observe fiducial marks. This portion of the scene is not necessarily the center of the scene. As such, the camera operator is constrained to look through the viewfinder in order for the autofocus system to focus the camera on the desired scene portion.
PCT published application WO 93/13452 discloses a camera having a light source that produces a beam of light extending in the direction the camera is aimed. A light pattern produced by reflection of the beam of light by an object informs the user where the camera is aimed. Actuation of a shutter trigger deactivates the light source and then actuates a shutter mechanism in the camera, with the camera at this time being properly aimed. The shutter trigger may also actuate an autofocus system.
As such, a camera user is not constrained to look through a camera view finder to aim the camera. However, there is no disclosure in WO 93/13452 that the light pattern indicates which portion of a scene the autofocus system is sensing. Therefore, the camera operator will still be required to look through the viewfinder in order for the autofocus system to focus the camera on the desired portion of the scene. As a result, the benefit of not having to look through the viewfinder to aim the camera is lost in the autofocus embodiment disclosed in WO 93/13452.
In the above cross-referenced applications 08/277,151 and 08/201,597, the visible light emitter (pointer) is part of the autofocus system. As such, the autofocus system requires that the visible light emitter emit light in order to properly function. However, in some situations it may be desirable to shut off the visible light emitter while still utilizing the autofocus system. Such shutting off of the visible light emitter while still being able to utilize the autofocus system is not provided for in 08/277,151 and 08/201,597.